Lowers your S197 Mustang approximately 1.5-inches;Dramatically improves handling;Lower center of gravity;Decreased body roll;Improved driver control;150lb/inch front linear spring rate;160lb/inch rear linear working rate, dual-rate spring;Designed for drag race application;Manufactured from chrome silicon high-tensile spring wire;Cold wound on a CNC Coiling Machine to exact specifications;Lifetime warranty against spring sag;Stress-relieved at 750 degrees F;Shot-peened;Computer tested for accurate height and spring rate;Made in the U.S.A.